Oakes 2010 - 8 Guidelines
INFANCY GUIDELINES FOR REPORTING EYE-TRACKING DATA -- Oakes, 2010 Describe the geometry of the testing situation and stimuli -- viewing distance, visual angle of stimuli (size and eccentricity), display area size (e.g., Frank et al, 2009, PNAS) Viewing distance = roughly 15 inches / 40 cm Size conversions: 1cm ~= 1.4 deg; 1 deg ~=0.7cm; 21.7 pixels per cm Monitor size (W X H) = 1024 X 768 pixels; 47.25cm X 29.75cm Stimulus characteristics Face positions: 8.5 cm distance between inner edges of faces (12 deg) Face sizes (W X H): 16.5 cm X 20 cm; 23 deg X 28 deg Eye ROI (W X H): 13cm X 3 Mouth ROI: Provide details about the eye-tracking system -- sampling rate, head movement accommodations (if any), quickness of recovery when track is lost, any proprietary automatic postprocessing of data (e.g., Petolta et al, 2009, Emotion) Fully describe the calibration procedure -- number and location of calibration points, human verification of calibration accuracy SMI calibration / validation custom bullseye: 2.75cm diameter; ~4 degrees --> TOO BIG??? position of center of bullseye: 9.5cm from vertical edge, 6.5 cm from horizontal edge; upper left and lower right corners (validation adds upper right and lower left positions); 13 degrees from vertical edges, 9 deg from horizontal edges Our calibration check movie bullseye: 2.25cm diameter, ~3 degrees --> good size Our centering stimulus bullseye: 2.25cm diameter, ~3 degrees (doublecheck this) Outline procedures used to deal with missing data -- what is filtered and how are filters defined (ie for blinks, saccades, head motion vergence)? Include details about how eye-movement data were processed -- any processing within proprietary software (pre or post)?; procedures for smoothing and noise reduction if any; interpolation across missing data points and to create continuous variable graphs Specify data reduction procedures and parameters '''-- what exactly is being reported and how was it calculated? any defined parameters (thresholds for time, dispersion, velocity, etc) '''Provide information about how REGIONS OF INTEREST (aka AOIs) were defined -- both show and tell; method of drawing (by hand, otherwise); how do ROIs vary across different stimulus exemplars? measure the relative size of the ROI (stimulus size/total display size; e.g., Gliga et al, 2009, Infancy Drawn by hand using SMI tools Provide complete information about exclusion criteria -- how many trials or what portion of trials? how many infants excluded altogether and why? DY's additional ideas for reporting eye-tracking data Demonstrate checks of data quality -- spatial accuracy, temporal completeness, whatever is important for the research question; post raw data, supplmentary graphs and full code for verification checks and generating all reported figures from raw data Aim to collect data in INTERPRETABLE UNITS, normally distributed and as close to raw as possible -- minimally or not at all smoothed/filtered/transformed; where filtering parameters are set, test effect of varying parameters on results (e.g., Wass et al, 2013, Behavior Research Methods; avoid complicated mathematical models that are not understood by the primary authors of the paper When comparing across age, measure and then control for any variability data quality and quantity -- for example, run adult data through a "baby filter" (introducing noise, removing datapoints, etc, as necessary)